Code for Quartz Scheduler
6.7k
Stars
2k
Forks
82
Open issues
30
Contributors
AI Analysis
Quartz is a mature, open-source job scheduling library for Java applications, ranging from standalone tools to large e-commerce systems. It serves developers who need reliable, feature-rich job scheduling and temporal task execution integrated into Java applications. Not intended for non-Java ecosystems or applications requiring real-time event streaming rather than scheduled batch operations.
Inferred from signals mentioned in the README (tests, CI, type safety) — not a review of the actual code.
AI's overall editorial judgment — not an average of the bars above, can weigh other factors too.
Quartz Scheduler: The veteran Java job scheduling library still actively maintained after 20+ years
Quartz is a mature, feature-rich Java job scheduling library enabling applications to execute tasks on a defined schedule — from simple cron-style triggers to complex calendaring rules. It supports clustering, persistence via JDBC, and integration with major Java frameworks including Spring. Originally built for enterprise Java applications, it remains widely used in legacy and greenfield Java backends. Its longevity reflects genuine utility, not momentum alone.
Quartz originated in the early 2000s, predating most modern scheduling alternatives. It was commercially backed by Terracotta (acquired by Software AG) before the GitHub mirror was established in 2016. It has shaped Java scheduling conventions that many frameworks later adopted.
Star growth is effectively flat (4 stars in the past 7 days), which is expected for a project this mature. Growth peaked years ago as Quartz became a de facto standard in Java enterprise environments. Spring's built-in Quartz integration continues to drive passive adoption without requiring new GitHub stars.
Quartz has documented integration in Spring Framework's spring-context-support module, which ships to millions of Java projects. Apache projects, legacy banking systems, and enterprise Java applications widely reference it. Maven Central download counts historically rank it among the most downloaded Java scheduling libraries. Adoption at scale is well-established, though direct production case study documentation in the README is minimal.
Likely follows a traditional plugin-based scheduler design: Jobs, Triggers, and a Scheduler interface form the core abstraction. Appears to support both in-memory (RAMJobStore) and JDBC-persistent (JDBCJobStore) backends, with clustering support through the persistent store. Build pipeline uses Azure DevOps CI according to the README badge.
Not documented in README
Last push was 2026-05-13, approximately 6 weeks before the evaluation date — indicating active, ongoing maintenance. The project is not stagnant; it is in a mature, slow-iteration phase consistent with stable infrastructure software. CI via Azure DevOps is confirmed operational.
ADOPT IF: you are building or maintaining a Java application that needs reliable, persistent, clusterable job scheduling with mature Spring integration and don't want to operate a separate scheduling infrastructure. AVOID IF: you need a distributed task execution platform with a web admin UI, worker node management, or cloud-native orchestration — modern alternatives like PowerJob or xxl-job are better fits. MONITOR IF: you are on Quartz 2.x and need to assess whether the project continues receiving security patches as Java LTS versions evolve.
Independent dimensions
Mainstream potential
3/10
Technical importance
7/10
Adoption evidence
8/10
- JDBC-based clustering requires a shared relational database, which introduces operational complexity and a potential single point of failure compared to newer ZooKeeper or Redis-based schedulers.
- No built-in admin UI or REST API for job management — teams must build their own operational tooling or use third-party wrappers.
- Slow release cadence in recent years may mean delayed support for new Java LTS versions or security fixes, though maintenance appears ongoing.
- Increasingly overshadowed in new Java projects by Spring's native scheduling abstractions for simple cases and by xxl-job/PowerJob for distributed cases, potentially shrinking the addressable niche.
- Community activity appears modest relative to project age — contributor diversity and issue resolution speed are not verifiable from available metadata.
Quartz will remain a stable, maintained choice for Java scheduling for the foreseeable future, sustained by embedded Spring usage, but is unlikely to recapture growth momentum as newer distributed schedulers claim greenfield projects.
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Languages
Information
- Website
- http://www.quartz-scheduler.org
- Language
- Java
- License
- Apache-2.0
- Last updated
- 2mo ago
- Created
- 126mo ago
- Analyzed with
- anthropic/claude-haiku-4-5
Stars over time
Contributors over time
Top 100 contributors only — repos with more will plateau at 100.
Open issues
Can I set the lockOnInsert property to false
Violation of PRIMARY KEY constraint 'PK_QRTZ_SCHEDULER_STATE'
Add support for multiple nth-day-of-month values
MySQL 8.0.30+: `liquibase.quartz.init.xml` fails if `sql_generate_invisible_primary_key` is enabled
XMLSchedulingDataProcessor#getJobGroupsToNeverDelete returns the wrong backing list
Open pull requests
PR: Introduce pluggable TimeBroker as replacement for system clock
build(deps): bump com.microsoft.sqlserver:mssql-jdbc from 13.2.1.jre11 to 13.3.0.jre11-preview
Modified interfaces to provide default methods where appropriate.
Top contributors
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xxl-job targets distributed task scheduling with a web-based admin UI and is significantly more popular in Chinese enterprise ecosystems. It offers executor-worker separation that Quartz lacks natively. Quartz is simpler to embed and has far broader Western enterprise adoption and Spring integration depth.
PowerJob is a newer distributed scheduler with workflow DAG support and a modern web console, positioning itself as a Quartz successor for cloud-native environments. Quartz lacks a built-in admin UI but has decades of production hardening and framework integration that PowerJob cannot yet match.
Spring's own scheduling annotations cover simple use cases without Quartz overhead. Spring Batch handles complex job workflows. Quartz fills the middle ground: persistent, clusterable, flexible scheduling without full batch processing semantics.
ElasticJob focuses on distributed, sharded job execution using ZooKeeper for coordination — a fundamentally different architectural model. Quartz is simpler to operate but lacks native sharding. ElasticJob is better suited for horizontally scaled data processing workloads.
A .NET port of Quartz sharing design philosophy and API conventions. They are ecosystem-separated (Java vs .NET) rather than direct competitors. The .NET version has slightly more GitHub stars, suggesting healthy parallel adoption in that ecosystem.